In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
USB: cdc-acm: skip URB restart in port_shutdown if disconnected<\/p>\n
acm_port_shutdown() is called from the tty-port machinery whenever the
\nlast user closes the port. acm_disconnect() sets acm->disconnected and
\ncalls tty_port_tty_vhangup(), which eventually triggers port_shutdown().
\nAt that point acm_disconnect() has already called acm_poison_urbs() and
\nis about to free the control and read URBs.<\/p>\n
However, acm_port_shutdown() unconditionally calls acm_unpoison_urbs()
\nand, when the ALWAYS_POLL_CTRL quirk is set, immediately re-submits the
\nctrlurb and all read URBs. If the concurrent acm_disconnect() then
\nfrees those URBs and their DMA buffers while they are in-flight, the
\nresult is a use-after-free in acm_ctrl_irq() or acm_read_bulk_callback()
\naccessing the freed DMA memory.<\/p>\n
Fix by checking acm->disconnected after draining the delayed anchor and
\nreturning early: if we are in a disconnect path the URBs must remain
\npoisoned and must not be resubmitted.<\/p>\n
The early return is placed after the delayed-anchor drain loop because
\nthat loop only cancels write-side accounting (wb->use = false and
\nautopm counter) and does not touch the hardware path.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
USB: cdc-acm: skip URB restart in port_shutdown if disconnected<\/p>\n
acm_port_shutdown() is called from the tty-port machinery whenever<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-41245","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/41245","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln"}],"about":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/types\/vuln"}],"wp:attachment":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=41245"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=41245"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=41245"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}